9,4,16,6,36,21,441?

• 9,4,16,6,36,21,441, 421
  
  9-5=4
  4^2=16
  16-10=6
  6^2=36
  36-15=21
  21^2=441
  441-20=421
• 11 years agoHelpfull: Yes(32) No(4)
• 9-4=5
  16-6=10
  36-21=15
  so 441-x=20==>x=421
• 11 years agoHelpfull: Yes(5) No(1)
• 421
  9-5=4
  16-10=6
  36-15=21
  441-20=421
  i.e we can sutract 5,10,15,20 from the previous answer
  
  
• 9 years agoHelpfull: Yes(3) No(0)
• 9-4=5,
  16-6=10,
  36-21=15;
  441-x=20;
  x=421(ans)
• 8 years agoHelpfull: Yes(0) No(0)